Search efforts continued Monday with five to 10 National Parks Service employees repelling with special gear into inaccessible areas, such as the Wickiup, Navajo and Spruce canyons, said Betty Lieurance, a public information officer.

"We don't have any dog teams out today," Lieurance said via email. "Helicopter support has been limited due to the fires in the state."

She said it is unusual for someone to be missing at the park this long, but her department will not give up looking.

Temperatures at the park on Monday were in the 80s.

"I wouldn't want to guess at how long someone could survive because you never know," Lieurance said.